In a conventional X-ray image diagnosis apparatus, a C-arm supports a pair of an X-ray generation apparatus and an X-ray detection apparatus being opposed each other. In recent years, an approach has been taken to improve diagnosis and treatment techniques through adopting an MAF (Micro Angiographic Fluoroscope) in this conventional X-ray detection apparatus to obtain a high-definition image of a small ROI (Region of Interest), such as a lesion. As this type of X-ray detection apparatus, a configuration equipped with, in addition to an X-ray detector having an eight to twelve-inch screen with a normal pixel size, a high-definition X-ray detector having many detection elements and a small-sized screen in the size of four to six inches with a smaller pixel size compared to a usual X-ray detector, is known. Specifically, there is a one-panel configuration in which a normal X-ray detector and a high-definition X-ray detector are integrated, and a two-panel configuration in which a normal X-ray detector and a high-definition X-ray detector are separately driven.
Spot fluoroscopy and ROI fluoroscopy techniques are known as an X-ray fluoroscopy technique using a catheter. In spot fluoroscopy, an X-ray diaphragm is controlled so that X-rays are irradiated only on an ROI designated by an operator, and X-rays outside of the ROI are shielded. Since X-rays irradiated outside of the ROI are shielded in the spot fluoroscopy, the exposure dose of a subject can be reduced. ROI fluoroscopy is a technique of X-ray irradiation which is carried out with an ROI filter being disposed, which has an opening region at least in a part, and is made of copper or aluminum, etc. Accordingly, the exposure of the X-rays passed through the ROI filter are attenuated in comparison to those in the opening region which is the ROI, thereby reducing an exposure dose of the subject.
When the aforementioned fluoroscopy technique and image display using the high-definition detector are performed in combination, it is necessary to match the ROI on which an operator carries out fluoroscopy with a detection region of the high-definition detector. This requires a position of the high-definition detector to be designated on an image in a manner so that a pre-set detection region of the high-definition detector matches with the ROI.